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Viruses normally seem like evil little germs; they often invade our bodies’ cells and hijack their inner machinery to mass produce viral invaders, which eventually destroy their host cells as they bust out to besiege more cells. The process repeats ad nauseam. But what if that wicked master plan could be twisted to do our bidding? What if viruses only invaded cells we wanted them to kill—like cancer cells?

Researchers got the initial idea of using viruses decades ago (PDF) and racked up a number of enticing anecdotes that suggested the idea could work. After all, cancer cells, in their altered state that allows them to replicate quickly and uncontrollably, often shut off their anti-viral defenses and are prone to infection. But scientists’ attempts at training viruses to be cancer assassins fell short in bigger trials—until now.

On Tuesday, the Food and Drug Administration approved the first viral-based cancer therapy. The virus, called talimogene laherparepvec (T-VEC), is a genetically engineered herpes simplex virus that can help treat advanced melanoma. Its genetic tweaks make it incapable of usurping normal, healthy cells. Thus, it doesn’t cause herpes. But when it meets cancer cells, it initiates cellular carnage. The virus is also engineered to carry a gene encoding the GM-CSF protein, which triggers the immune system. As the virus ravages cancer cells, GM-CSF gets released, boosting a patient’s natural defenses.

So far, T-VEC isn’t a wonder drug, but it’s helpful. In a large clinical trial published in May in the Journal of Clinical Oncology, researchers found that the virus shrank tumors and extended patient survival by a median of 4.4 months. The results were just shy of showing a statistically significant benefit to overall health. Still, the researchers are hopeful that when the viral therapy is combined with traditional therapies, it could significantly boost survival rates in patients.

And with T-VEC’s approval, researchers see a clear path for more viral-based remedies. Many such therapies are already in the works, and researchers are combing through the large varieties of viruses for the next potential cancer slayer.

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I currently work on this program--there's some interesting combination therapies for a variety of different tumor sites that are suggesting substantially improved response rates compared to using just one of the therapies alone. Expect to see initial read outs of these new trials in the next 2 years or so.

And with T-VEC’s approval, researchers see a clear path for more viral-based remedies. Many such therapies are already in the works and researchers are combing through the large varieties of viruses for the next potential cancer slayer.

I think this is perhaps the best news I've read on the cancer front in a very long time.

Great job!

Yours for only $126,222.15 per treatment!Oh, and not covered by insurance, of course.

One key problem with genetic meddling of food crops is that you by definition have to "let the genie out of the bottle" and contaminate the entire environment.

That genie is so far out of the bottle at this point, that the bottle was discovered in some archaeological dig.

Fun fact: We've been genetically modifying our food from the moment we started actively raising it. It's just that the lab is a lot more precise and less prone to things like poisonous potatoes or celery that causes sun sensitivity than the "time tested" methods we've been using for millennia.

Isn't it exhausting to live with so much fear and ignorance of the world at large?

The 19th century was the century of chemistry.The 20th century was the century of physics.The 21st century will be the century of biology.

I expect to see many more advances like this. Maybe by the time I get to be the ripe old age of my parents, understanding and technology will have developed to the point where I'll be more comfortable and not suffer from the same ailments they do. Or I suppose more likely, there will be a new set of ailments. That assumes AI doesn't kill us all before then.

I currently work on this program--there's some interesting combination therapies for a variety of different tumor sites that are suggesting substantially improved response rates compared to using just one of the therapies alone. Expect to see initial read outs of these new trials in the next 2 years or so.

Hi Stories,

Is this based on the CART work similar to what Dr. Porter was doing with CLL? I noticed that in his work it was lentiviral vector. This seems to be a herpesviridae vector (based on the post here). I recall that Dr. Porter was planning to tackle melanoma next because many forms of over-expressed a similar receptor (For CLL they targeted all CD19-expressing cells).

No, TVEC doesn't bind specifically to any particular cell surface markers. Unlike CART, which is a retrovirus, TVEC is actually a virus with the ICP34.5 gene turned off so it can't initiate initiate host protein synthesis in differentiated cells.

TVEC in its current state, won't be applicable to hematologic malignancies such as CLL as it has to be injected directly into the site of the malignancy. In that space, bispecific antibodies are showing a lot of promise and recently, a treatment in that space was also recently approved (blinatumomab) for the treatment of ALL (the acute, fast version of CLL). Amgen and KITE both have several molecules in the pipeline.

From what I understand this virus is genetically modified; engineered. Really no different from GMO food sources.

With public opinion of GMO based food going down (due to pseudo-science or real science, I can't tell) I wonder what opinion (public or expert) will be given to this virus based treatment.

Is this not the premise of I Am Legend?

Then refuse treatment. Then we can get the anti-science crowd out of the population at a slightly faster rate.

Maybe we can publish an article about how bad this technology is in some of the more egregious pseudoscience rags to get the attrition rate to ratchet up another notch.

This is a dangerous path to be treading and no one should try to minimize this fact. Your "science uber alles" mentality is really no better. One key problem with genetic meddling of food crops is that you by definition have to "let the genie out of the bottle" and contaminate the entire environment.

Hopefully this therapy is a little more contained than that.

Good news is that HSV has a very low mutational rate which makes HSV an ideal candidate for use as an oncolytic virus. As the first MOA of it's kind, TVEC will be monitored heavily in post-marketing studies for any evidence of viral shedding. Initial evidence suggests this isn't an issue, but you never know long-term. Of course, another issue is that advanced melanoma (the indication for TVEC) is a very aggressive disease with short survival... so it'll be interesting to monitor what happens over time.

If it has to be injected directly into a lesion to be effective, it has a very narrow window of usefulness. What kills you are the metastases, which are typically not accessible that way. In the case of melanoma, you may be able to treat skin lesions, but on its own, that would not be much of an advance.

Hopefully, there are immune consequences to the virus effects, beyond the nonspecific stimulus of GMCSF you mentioned, but without having looked at the details of this approach, I suspect the interventions directed at re-awakening the immune system with agents against inhibitory receptors such as CTLA4 and PD1 are more promising.

If it has to be injected directly into a lesion to be effective, it has a very narrow window of usefulness. What kills you are the metastases, which are typically not accessible that way. In the case of melanoma, you may be able to treat skin lesions, but on its own, that would not be much of an advance.

Hopefully, there are immune consequences to the virus effects, beyond the nonspecific stimulus of GMCSF you mentioned, but without having looked at the details of this approach, I suspect the interventions directed at re-awakening the immune system with agents against inhibitory receptors such as CTLA4 and PD1 are more promising.

Internal organs can be injected, as well, so it won't be limited to just melanoma. The MOA also isn't specific to melanoma, in particular, so a number of different solid tumor sites are currently under investigation. The most promising areas (as suggested in the article) is combo therapies. Combination therapies are currently undergoing trials. In particular, there's suggested synergistic effects leading to more than just additive response rates compared to either agent alone. These trials should start reading out over the next 2 years.

I think the hope is, this is one more agent with a novel MOA that can be used with other agents to further improve response rates and lead to longer remissions. Most drugs when they debut, particularly for novel MOA, initially target diseases that are the most extreme (e.g. relapse/recurrent advanced disease) and then begin new trials in earlier lines of therapy if there's suggestions that it could be more effective than the current standard of care.

Ars, please make a quick check about the Cannabis treatments efficiency. Research from last years shows good results in many cases, with minimal side effects (reported by Ars too)And please write about the politics and interests groups. Technology is just the tip of the ice

The virus, called talimogene laherparepvec (T-VEC), is a genetically engineered herpes simplex virus that can help treat advanced melanoma. Its genetic tweaks make it incapable of usurping normal, healthy cells. Thus, it doesn’t cause herpes. But when it meets cancer cells, it initiates cellular carnage. The virus is also engineered to carry a gene encoding the GM-CSF protein, which triggers the immune system. As the virus ravages cancer cells, GM-CSF gets released, boosting a patient’s natural defenses.

Wonderful, descriptive prose.

I thought it was rather hyperbolic, personally. "Cellular carnage" against cancer cells sounds great, until you read that it extended life by 4.4 months and is thus nowhere near being a real cure. Many researchers are very guilty of using superlatives when they aren't really warranted.

If you were told you only had 4 months to live, this would double that. Don't be a hater.

And with T-VEC’s approval, researchers see a clear path for more viral-based remedies. Many such therapies are already in the works and researchers are combing through the large varieties of viruses for the next potential cancer slayer.

I think this is perhaps the best news I've read on the cancer front in a very long time.

Great job!

Yours for only $126,222.15 per treatment!Oh, and not covered by insurance, of course.

And with T-VEC’s approval, researchers see a clear path for more viral-based remedies. Many such therapies are already in the works and researchers are combing through the large varieties of viruses for the next potential cancer slayer.

I think this is perhaps the best news I've read on the cancer front in a very long time.

Great job!

Yours for only $126,222.15 per treatment!Oh, and not covered by insurance, of course.

Oh you Americans are adorable with your price on health and non-universal insurance!

Except Europeans "ration" this kind of stuff. Drugs that are covered in the US aren't in other European countries. Coverage might suddenly stop when the budget runs out. Restrictions on expensive therapies are tighter. Even basic diagnostics seem to be in short supply despite the fact that you should be cutting out the middleman and making things cheaper.

If anything the American system is MORE likely to be aggressive saving your life. Plus this stuff is being developed here.

It is not rationed as much as analysed and only offered if the price is reasonable. If a company charges x100 for a drug that is only marginally better than the now inexpensive predecessor, it is likely not to be offered for free, if they only charge x2 for it, it is. For treatments like this, it will depend on how effective they are compared to cost. American insurance companies does they same, but have much much weaker price negotiation power and end up paying a lot more than European public insurances.

I currently work on this program--there's some interesting combination therapies for a variety of different tumor sites that are suggesting substantially improved response rates compared to using just one of the therapies alone. Expect to see initial read outs of these new trials in the next 2 years or so.

Is this an application of the science around CRISPR? I listened to a Radiolab podcast about it a few weeks ago, and it sounds really interesting.

The virus, called talimogene laherparepvec (T-VEC), is a genetically engineered herpes simplex virus that can help treat advanced melanoma. Its genetic tweaks make it incapable of usurping normal, healthy cells. Thus, it doesn’t cause herpes. But when it meets cancer cells, it initiates cellular carnage. The virus is also engineered to carry a gene encoding the GM-CSF protein, which triggers the immune system. As the virus ravages cancer cells, GM-CSF gets released, boosting a patient’s natural defenses.

Wonderful, descriptive prose.

I thought it was rather hyperbolic, personally. "Cellular carnage" against cancer cells sounds great, until you read that it extended life by 4.4 months and is thus nowhere near being a real cure. Many researchers are very guilty of using superlatives when they aren't really warranted.

I currently work on this program--there's some interesting combination therapies for a variety of different tumor sites that are suggesting substantially improved response rates compared to using just one of the therapies alone. Expect to see initial read outs of these new trials in the next 2 years or so.

The other therapies involve the use of new products or combination with existing cancer medicine?

I currently work on this program--there's some interesting combination therapies for a variety of different tumor sites that are suggesting substantially improved response rates compared to using just one of the therapies alone. Expect to see initial read outs of these new trials in the next 2 years or so.

The other therapies involve the use of new products or combination with existing cancer medicine?

The combination therapies are with newly released or currently undergoing trials for approval.